GL4ES SDK for AmigaOS4
=== What is GL4ES
GL4ES is an OpenGL 2.1/1.5 to GL ES 2.0/1.1 translation library, with support
for Pandora, ODroid, OrangePI, CHIP, Raspberry PI, Android and AmigaOS4.
For AmigaOS4 translation done via ogles2.library (written by Daniel "Daytona"
Mubener), and which in turn works on top of warp3dnova.library (written by Hans
de Ruiter).
Minimum requirements for ogles2.library are 2.8 and for warp3dnova.library it
should be 1.65
With GL4ES we have not only OpenGL1.x as with MiniGL, but OpenGL 1.x, OpenGL2.x
and even some limited OpenGL3.x support.
Also it is faster than MiniGL and bug-less.
Written by Sebastian "ptitSeb" Chevalier. AmigaOS4 version handled by kas1e, but
all actual AmigaOS4 related code still done by ptitSeb.
Actual code: https://github.com/ptitSeb/gl4es
Main site: http://ptitseb.github.io/gl4es/
=== What is GL4ES SDK for AmigaOS4
GL4ES SDK for AmigaOS4 come not only with gl4es link library, but also with set
of other link libraries which help to use it more widely, such as SDL1, SDL2 and
GLU.
Currently in the first release of SDK it contains those libraries:
libgl4es.a : gl4es (r1.974, Sep 7, 2019) : https://github.com/ptitSeb/gl4es
libgGLU_gl4es : GLU (9.0.0, Apr 15, 2018) : https://github.com/ptitSeb/GLU
libSDL_gl4es.a : SDL1 (1.2.15, Sep 1, 2019) :
https://github.com/AmigaPorts/SDL/tree/SDL-1.2
libSDL2_gl4es.a : SDL2 (2.0.8, Apr 9, 2019) :
https://github.com/AmigaPorts/SDL/tree/master
While actual AmigaOS4 changes are in gl4es & glu repos, SDL1/2 changes related
to handling of GL4ES still not on github, as at the moment it's still unclear
how to handle that all better:
- or to put them to original repos and made a way to choose with what support
to compile (MiniGL or GL4ES).
- or to just make separate branches, where remove MiniGL and keep only GL4ES,
so that there is no chaos in the repositories.
- or to find some other clean-to-handle way.
In other words at the moment in terms of SDL only ready to use static link libs,
without actual code changes (in which probably no one interested if everything
works)
=== How to install
1. Be sure that you have installed original SDL1, SDL2 and OpenGLES2 SDK
SDL1: http://os4depot.net/share/library/misc/sdl.lha
SDL2: http://os4depot.net/share/library/misc/sdl2.lha
OGLES2 SDK : that one can be taken together with ogles2.library itself from
Enhancer pack.
2. Put gl4es_sdk's libraries to SDK/local/newlib/lib/
3. Put gl4es_sdk's GL includes to the place where you have old MiniGL ones
(don't forget to save them, to something like GL_save_minigl).
It can be in SDK/local/common/include/GL or in SDK/local/newlib/include/GL.
Just be sure nowhere else old MiniGL includes will be taken.
4. For SDL1, in SDK/local/newlib/include/SDL/SDL_opengl.h comment out include of
<mgl/gl.h> (so to avoid name conflicts and co).
For SDL2 no such include used, so no conflicts there.
One may ask, why remove MiniGL includes, and why not put GL4ES includes to some
directory like GL4ES instead of GL (so to not touch MiniGL ones) : yes, you can
do that. Just when you will later work with GL4ES,then everywhere and every time
you will be in needs to change include of opengl includes from GL to GL4ES
directory. And when sometime in your sources you will forget or miss to do so,
then you will have name conflicts and clashes. But you can choose the way you
want, of course. I just find it easier to have it in GL.
=== How to use:
If you want to use pure AmigaOS API + GL (without SDL) , you need to use ogles2
context instead of minigl one. You shouldn't use directly any agl* functions
from ogles2.library, but instead their alternatives from gl4es: they have the
same name, just before calling original agl* ogles2 function, in wrapper ones
done some internal for gl4es things. For developer it is a matter of only adding
necessary defines. I rewrote few random minigl examples from minigl distributive
to make them works over gl4es and put them to Examples/from_minigl, so you can
see how to work with pure AmigaOS4 API + GL4ES.
If you want to use SDL1/2, then there nothing need to be changed, only compiling
lines changes from -lSDL -lGL -lGLU , to -lSDL_gl4es -lglu_gl4es -lgl4es , or to
-lSDL2_gl4es if SDL2 in use.
Examples directory also comes with some SDL1 examples (just a few randomly taken
nehe's tutorials, with amigaos4 makefile), as well as with with some random SDL2
examples which I take from the google, adapt a bit, and made a makefiles for.
Remember, that GL4ES can be also controlled via environments a lot (that, of
course, includes AmigaOS4 version too, where you just control envs via "setenv
LIBGL_xxx xx"). Full list of environments and their description can be found in
Documentation/GL4ES/USAGE.md
=== How be up to date:
I hope to update SDK from time to time with newer version of gl4es, SDL1 and
SDL2 libraries, but you always can go to https://github.com/ptitSeb/gl4es , and
build up2date version yourself.
For myself, I do it all on crosscompiler (cygwin) and to build it I just do:
cd gl4es-master
mkdir build
cd build
cmake
-DCMAKE_SYSTEM_NAME=Generic
-DAMIGAOS4=1
-DSTATICLIB=ON
-DCMAKE_SYSTEM_VERSION=1
-DCMAKE_BUILD_TYPE=Release
-DCMAKE_C_COMPILER="/usr/local/amiga/bin/ppc-amigaos-gcc"
-DCMAKE_CXX_COMPILER="/usr/local/amiga/bin/ppc-amigaos-g++"
-DCMAKE_LINKER="/usr/local/amiga/bin/ppc-amigaos-ld"
-DCMAKE_AR="/usr/local/amiga/bin/ppc-amigaos-ar"
-DCMAKE_RANLIB="/usr/local/amiga/bin/ppc-amigaos-ranlib"
-DCMAKE_FIND_ROOT_PATH="/usr/local/amiga/ppc-amigaos/"
..
make -j4
And in build/lib directory you have libGL.a, which you just rename after to
libgl4es.a
=== Thanks to:
to ptitSeb for gl4es and all his help with everything :
https://github.com/ptitSeb/gl4es/
to Daniel for OpenGL ES2 and all his help with everything :
http://www.goldencode.de/
to Hans for Warp3DNova and all his help with everything :
https://keasigmadelta.com/
to Capehill for actual SDL1 and SDL2 ports and all his help with everything:
https://github.com/AmigaPorts/SDL
to others for help and tests
(c) kas1e, 10 sep 2019

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